I have one host in my network that doesn't get the IPv6 address I've reserved for it in OpenWrt.
I've several Fedora 28 hosts and all get their assigned IPv6 correctly, except this one. It has '10' as its IPv6 suffix, but it always get the IP ::130. I've triple checked that the DUID is correct.
Can the DHCPv6 clients ask for a specific IP? Maybe it had that IP assigned time ago and is somewhere stored in NetworkManager and keeps asking for it.
Ok, in the first package, the client informs of the ::130 address in something called "Identity Association for Non-temporary Address", so I guess is trying to get that address. I've tried to delete all archives in /var/lib/NetworkManager to try to forget that address without luck.
Somehow it has that address "stuck in its mind" and asks for it from the DHCPv6 server. Do you see the OFFER, REQUEST, and ACK as well, or has the client "gone rogue" with that address?
You might want to find out where Fedora stores its acquired DHCP leases and remove at least the DHCPv6 content there.